ML20080G528
| ML20080G528 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 02/07/1984 |
| From: | Schroeder C COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 8102N, NUDOCS 8402130428 | |
| Download: ML20080G528 (5) | |
Text
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/nN Commonwealth Edison
/
) On3 First NLtional Plaza. Chicago, Illinois
(
J Address Reply to: Post Office Box 767 a
'qj Chicago, Illinois 60690 February 7, 1984 PRINCIPAL STAEF 9.A' JPRFV N) f- /
3/Rh DE V
Mr. J. G. Keppler, Regional Administrator
[
(,[
Region III aAo scs-U.S. Nuclear Regulatory Commission ggg
.g 799 Roosevelt Road ENF File i r
Glen Ellyn, IL 60137
Subject:
LaSalle County Station Unit 1 High Drywell Temperature NRC Docket No. 50-373 References (a):
C.
W.
Schroeder letter to J.
G. Keppler dated December 22, 1983, transmitting report on Unit 1 High Drywell Temperature.
(b):
C. W. Schroeder letter to J.
G. Keppler dated December 27, 1983, supplementing the above referenced report.
(c):
C. E. Norelius letter to Cordell Reed dated January 13, 1984, requesting followup reports on Edison commitments on this subject.
Daar Mr. Keppler:
This letter indicates the results achieved on LaSalle Unit 1 for the high drywell temperature situation.
This report supplements the reference-(a) and (b) submittals and responds to Item 1 of Reference (c).
It discusses the actions taken on Unit 1 and the results observed in the drywell thermal measurements program with sensible heat present.
The submittal date for this report has been discussed with Mr. R. Walker l
of your staf f.
l A'two-iteration damper trimming exercise on Unit 1 resulted in drywell air flow settings that produced acceptable temperatures with the l
cugmented air ducted into the upper drywell regions.
The bulk tcmperature remained'within acceptable limits and no equipment temperatures exceeded allowables.
The resulting average drywell temperature was verified for Unit
'l to be less than the 1350F design value recorded in the FSAR and roferenced in the Technical Specifications.
A comparison of the drywell cverage return temperature and the calculated volume-weighted temperature is as follows:
8402130428 84 8 1984 i
PDR ADOCK 05000373 FEB P
PDR m f IIs
y
- L o
'J.
G. Keppler' February 7, 1984 Computed
' Power? Level Volume Weighted _
Average
- Correlated Sensors **
Return ITE-VP083 ITE-VP076 (MWE).
'(Bulk) Temp 0F Temp 0F OF OF 150-115.3-113.3 116.7 115.1 752 122.3-121.3 121.9 120.3 895-127.3 127.5 127.6 127.1-
- Ra t ed -.
.130.6 (est)?
- ThekTE-VP033and034~sensorsonthereturnairductareusedin
.the Tech Spec to represent' average drywell temperature.
- Note:that these-two. temperature sensors 1TE-VP083 and ITE-VP076 represent the average drywell temperature fairly accurately for the modified flow configuration (after trimming) for the at power condition.
1 The specificirequest of Item 1 in Reference (c) is fulfilled via Jthe ' attached-Figure which compares the before and-after fixes thermal i
profile.
The limiting condition.is an ambient temperature of 1480F
'ncar the S AN solenoid. 'This is within Technical Specification 3/4.7.7 for LaSalle, which fulfills an objective of the short-term fix with respect ato protection of safety related ' equipment.
.. Analytical predictions of " remaining life" for the installed -
IMF-2csolenoids based upon the EQ test data from Wyle Laboratories for this device is. indicated below, along with predictions of " remaining
-l'ife": based upon EQ analyses of the weak-link materials.
Remaining' Life for IMF-2 Solenoids on Safety Relief Valves 4
Lifetime
. Original
. Adjusted 2 Consumed 3 Life Remaining 4 Basis Lifel for
. Life for 14560F6 210 Life at X0 1350F 1520F Ambient Ambient Ambient Unit.17
' Test'* ~ years 1 1/2 years all None, 152
. Analysis **
44 40 years 3.6 years 40 y r., 152 Unit *2
-Test
- 5 : years 1 1/2' years 0
2.7 y r. 152 Analysis ** '44 40 years 0
44 y r., 135 h
' Solenoid booy te.nperature (OF) equals 0.916 (ambient temp) + 46.2.
- f J. G.lKeppler February 7, 1984 o -
Cat I Test was 141 hr. at 3290F for thermal aging equivalent for 10 year life at 1350F ambient service plus a LOCA accident exposure.
' (Wyle Test Report 44220-2.)
o* ~ Cat II Qualification by' Analysis based upon Material properties for RTV-732 (0.77 ev activation from Wyle Materials Data Bank).
1.
Original -qualification basis to NUREG 0588 Cat I (EQ-LS-041, EMD 030803).
2.
Adjusted life for worst case high drywell temperatures projected from drywell flow conditions observed in Preoperational Tests.
3.
That. part of qualified thermal life used (or aged) during past over-temperatures in upper. drywell region; calcualted from Unit 1
. time-temperature histograms.
4 Qualified thermal life remaining after subtraction of consumed (aged) life and allowance for LOCA accident apportionment from the whole life capability of the most limiting material in the solenoids (Basis is Wyle Laboratories Material Data Bank, Wyle Lab Report 44220-2 and Crosby Test Report 3977 dated May 6, 1982).
The solenoids from the hottest location in Unit 1 are scheduled for proof. testing at Wyle Laboratories to validate these analytical
. predictions of " remaining life".
The test plan for that testing has been
- in preparatio during the second half of January 1984.
This report is intended to fulfill the specific request of Item
. 1 in Reference (c); details of the analysis are available for inspection ot the station-or at SNED in downtown Chicago.
A working-level discussion:may be the best way to respond to detailed questions on the methodology or data base.
Edison would be pleased to host such a meeting s
or to participate with your reviewers at the station or some other location.
It is noteworthy - that drywell teraperature limits were not exceeded during the' restart of Unit 1 to sequentially establish the air-flow settings inside containment.
It should also be noted that at no
-time did the Unit 1 high drywell temperatures result in erratic water lovel indications traceable 'to flashing or boiling in the reference legs of.the water level sensors.
Responses on Items 2 and 3 of Reference (c) must of necessity be daferred, respectively, for calendar-time and for final selection of the long term corrective actions now ander study.
Additional detail on the letter topic is included in a sepLrate summary report on Unit 2 drywell Ltcmperatures.
rn J. G.-Keppler February 7, 1984 cTo.the best. of my knowledge and belief the statements -contained
_!^
herein and in the' attachment are true and correct.
In some respects these_ statements are not based on my personal knowledge but upon infor-
- mation furnished by other Commonwealth Edison and contractor. employees.
Such_information has been' reviewed in accordance with Company practice end-Ifbelieve it to be reifable.
If there are any further questions regarding this matter, please contact this office.
Very truly yours, zbfB4 C. W. Schroeder Nuclear Licensing Administrator CWS/Im Attachment cc:
NRC Resident Inspector - LSCS 8102N 1
L..
coM PA R I S'O A/
OF I bf lTI A L A N D.
MODIFI E D vE RTICAL DRYWELL. THERMAL PROFILE - UNIT f BEFDRE FIXIES.
AFTER FIXE 5 2
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(DUCT OUTLET)
EL 804'- 6" f
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222*p 200,7. F
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197*F
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